Methods for data transmissions, the corresponding transmission protocols in particular, are used everywhere where large amounts of data, referred to in the following as messages, are to be securely transmitted in small packets, referred to in the following as data telegrams or also data frames. A CAN telegram (CAN: controller area network), for example, allows transmission of a certain number of useful bytes. If larger packets or amounts of data are to be transmitted, a transmission protocol must be used for the segmentation of these messages at the sender or the assembly at the receiver.
The ISO (International Standardization Organization) has issued standard 15765 in particular for diagnostic applications. A transmission protocol, in which no confirmation of the transmitted messages takes place within the scope of a data transmission, is specified in part two of the ISO standard 15765-2. In addition, acknowledgements are often not needed, since data or messages containing certain information are sent cyclically in different applications, in the automobile industry in particular. If data, a message in particular, is lost in the process, synchronization of the lost data simply takes place in the next message.
However, if messages are exclusively transmitted in an event-driven manner, an absent confirmation of the message is not acceptable.
Possible approaches to the problem of the absent confirmation, in CAN-based systems in particular, result from the fact that a transmission protocol, exclusively provided for this purpose, is used, this transmission protocol, however, having the disadvantage of being incompatible with protocols required for a plurality of applications within the diagnostic scope in the motor vehicle, or that the required confirmation is executed on higher protocol layers, known as an additional security layer, resulting disadvantageously in substantially higher costs at a higher error rate, as well as in greater inefficiency, in particular due to a higher bus load.